Safety fuel pump system



W. G- HERRIDGE, JR

SAFETY FUEL PUMP SYSTEM Filed March 21, 1960 GZ/VRATO/Q Dec. 11, 1962 IN VEN TOR. fizz/2w? BY Z Tmmwgy United States Patent ()fifice 3,068,364 Patented Dec. 11, 1962 3,068,364 SAFETY FUEL PUMP SYSTEM William G. Herridge, Jr., Anderson, Ind, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Mar. 21, 1960, Ser. No. 16,379 6 Claims. (Cl. 307-10) This invention relates to pump systems and more particularly to electric fuel pump systems suitable for use in automobiles having internal combustion engines.

If an electric fuel pump is used in an automobile, steps must be taken, as a safety measure, to provide means whereby such a pump is automatically deenergized in the event the engine of the vehicle is stopped. This is to prevent fiooding of the engine carburetor, or in the case of a road accident, to reduce the potential fire hazard.

An object of the present invention is to provide an improved fuel pump system of simple circuitry and possessing an automatically operative safety feature assuring no pump discharge when conditions other than normal are experienced.

A feature of the present invention is a fuel pump system having circuitry involving an engine starter and having an electric fuel pump adapted to be connected to a voltage source such as a battery during engine starting, two magnetically operated relays being arranged automatically to shift the pump voltage supply to the generator circuit of the engine when the latter runs and also automatically to deenergize the pump when the engine stops.

These and other important features of the invention will now be described in detail in the specification and then pointed out more particularly in the appended claims.

The drawing depicts a diagrammatic view of an electrical fuel pump circuit in which the present invention is embodied. An internal combustion engine, not shown, is conventionally arranged to be started by a motor 10 and to drive a generator 12. The latter are grounded as at 14 and 16 respectively. A battery 18, arranged to serve as a voltage supply source, is grounded at 20. A starter switch 22 is provided with two contacts 24 and 26. A relay 30 of the single pole, double throw variety, is provided to control operation of an electric pump 32 which is grounded at 34. The generator circuit is controlled by a single pole, single throw relay 36 conventionally known as a generator cutout relay for connecting the generator 12 to the battery 13 only when the generator voltage reaches the value for which the relay is set. A stack of selenium rectifiers or a semiconductor device could be used in place of the more conventional relay 36. The pump control relay 30 has contacts 40, 42 and 44 and an operative coil 46 with one end 47 connected to the ground at 43. An arm carrying the contact 40 is connected by a line 56 to the pump 32. The cutout relay 36 has an operative coil 52 with one end 53 connected to the ground at 54. This relay also has two contacts 56 and The contact 56 is connected by a line 60 to the battery .3, The contact 58 is carried by an arm 62 positioned to be actuated by the coil 52 and connected by a line 64 to an intermediate portion of that coil. A line 66 is provided connecting the coil to the generator 12 and the contact 44 of the relay 30. The line 60 is connected by a line 68 to the starter switch contact 24. The contact 26 is connected by a line 70 to the motor and to the coil end 72 and contact 42 of the pump control relay 30. In the latter relay, the contact 40 is normally closed with respect to the contact 44 as shown in the drawing and normally open with respect to the contact 42. In the relay 36, the contacts 56 and 58 are normally open as shown in the drawing.

The operation of the pump circuit is as follows: When it is desired to start the engine, the switch 22 is manually operated to close the circuit to the motor 10. The coil 46 of the relay 30 is simultaneously energized causing the relay armature or arm with its contact 40 to close the pump circuit through the contact 42. The pump 32, therefore, operates and continues to operate while the switch 22 remains closed. When the engine starts, the generator 12 generates a voltage which closes the contacts of the cutout relay 36. The starter switch 22 will then be open deenergizing the cranking motor 10 and allowing the relay 30 contacts to return to their normal position as shown in the drawing. The time required for the contact 4% to switch from the lower contact 42 to the upper 44 is not sufficient to affect running of the engine. The pump 32 is now connected through the relay 30 to the generator circuit and the latter is connected by the relay 36 to the battery 18. The pump is caused to operate while the generator 18 is generating current. If the engine stops, the lack of generator voltage will open the relay 36 disconnecting the generator and pump from the battery to prevent operation of either by the battery. With the generator not operating the pump will not operate until either the starter switch 22 is closed or the generator is ,supplying current.

There are at least two added advantages to the arrangement. One is that there is no current drawn by the relay ,3!) as the engine operates and another is that the pump 32 will operate although there may be a solenoid defect in the relay 30 or in means for operating the switch 22, providing the engine can be started or is running.

I claim:

1. A fuel pump system for an internal combustion engine, said system including a voltage supply source, an electric fuel pump, two electromagnetically operated relays, an engine starter circuit including a starter motor and a starter switch connected to said voltage supply source, a generator circuit including a generator and one of said relays, said one relay having normally open contacts arranged when closed to connect said voltage supply source to said generator, the other of said relays having three contacts of which two are normally closed to connect said generator circuit to said pump, and the third contact of said other relay being adapted to be connected to said motor circuit and to said pump when said two contacts are open.

2. A fuel pump system as set forth in claim 1, the said one relay being a single throw switch and the other relay being a single pole, double throw switch.

3. A fuel pump system including an electric fuel pump, an electromagnetically operated relay, a voltage supply source such as a battery, a generator circuit, a pump circuit for operating said pump including the other of said relays, an engine starter motor, a manually operative switch operative to energize said starter motor and said voltage supply source, and the arrangement being such that lack of generator voltage will cause said relay automatically to stop said pump.

4. A fuel pump system including two relays and a battery, a generator circuit including a generator, one of said relays and said battery, a pump circuit including an electric pump, the other of said relays, an engine starter ing normally closed contacts connecting said generator to said pump and normally open contacts adapted to close and connect said pump to said switch.

6. A fuel pump system for an engine including a battery, an electrically operated fuel pump, a voltage generator, an engine starting motor circuit, a two position relay normally connecting said generator to said fuel pump for operating the same, said relay connected to said References Gated in the file of this patent UNITED STATES PATENTS Robey Apr. 13, 1948 Gallina Oct. 25, 1949 

